1. Field of the Invention
This invention relates in general to battery backup systems, and more particularly to a method and apparatus for monitoring the battery capacity of the battery backup system and for compensating the RF output power to increase the service availability of the cellular base station service during disconnected external power supply conditions.
2. Description of Related Art
Cellular communication systems are experiencing tremendous growth in the global communication market place. This growth is fueling many research programs and expanding the technology opportunities for all manufacturers of cellular equipment.
To attract customers and obtain a larger market share, cellular providers are pushing features enabled by the system""s purely digital nature, such as Caller ID and short messaging, a paging equivalent. To further obtain a larger market share, cellular providers have turned to reducing the cost of air time. Cutting prices can take many forms. For example, vendors can give more free minutes per month, charge less for additional minutes, charge nothing for the first minute of incoming calls, reduce monthly fees, eliminate long-term contractsxe2x80x94all tactics available to the established cellular vendors as well. For a provider, this leads to less revenue per customer, but more incentive for increasing the market share. Thus, any reduction in customer traffic due to network problems has a tremendous impact on revenues and profits.
During an electrical power outage at a cellular base station site, the battery backup system is designed to maintain the operation of the base station until the electrical power is restored. Depending on the design of the battery backup system, the battery capacity, or the duration of the electrical power outage, the cellular base station may actually be forced to shut off and experience a certain amount of down time. This down time is directly related to the reduction in service availability and loss of network operator income. However, there is no commonly known method for monitoring the actual battery capacity of the battery backup system and compensating the RF output power to increase the service availability of the cellular base station service.
It can be seen that there is a need for a method and apparatus for monitoring the battery capacity of the battery backup system and for compensating the RF output power to increase the service availability of the cellular base station.
To overcome the limitations described above, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention discloses a method and apparatus for monitoring the battery capacity of the battery backup system and for compensating the RF output power to increase the service availability of the cellular base station.
The present invention solves the above-described problems by providing compensation of RF output power when the battery back-up system is in use for a cellular base station. By monitoring the battery capacity and power consumption of the cellular base station, the RF output power can be compensated. This compensation in RF output power will increase the time that the cellular base station can operate within the battery backup mode. This therefore increases the cellular base station service availability and does not allow for any loss of network operator income.
A method in accordance with the principles of the present invention includes monitoring a capacity of the battery backup system during a time interval, during the time interval monitoring a power level of a signal generated by the transmitter and compensating the output power of the signal generated by the transmitter to increase the lifetime of the battery backup system.
Other embodiments of a system or method in accordance with the principles of the invention may include alternative or optional additional aspects. One such aspect of the present invention is that the monitoring of the capacity of the battery backup system and the power level of the signal generated by the transmitter occurs at predetermined time intervals.
Another aspect of the present invention is that the compensating further comprises calculating a power consumption by the transmitter, the calculated power consumption corresponding to a predetermined time interval.
Another aspect of the present invention is that the compensating further comprises decreasing the power level of the signal generated by the transmitter to reduce the power consumption by the transmitter.
Another aspect of the present invention is that the transmitter comprises a power amplifier, the power amplifier generating the output signal to the mobile terminal.
In one embodiment of the invention, a base station includes a transmitter coupled to a primary power supply, the transmitter generating a radio signal at a controlled power level to a mobile terminal, a battery backup system, coupled to the transmitter, for providing system power to the transmitter during a failure of the primary power supply, the battery backup system having a capacity determining a time period that the battery backup system can provide system power to the transmitter, and a processor, coupled to the transmitter and the battery backup system, for monitoring a capacity of the battery backup system and the power level of the signal generated by the transmitter and compensating the output power of the signal generated by the transmitter to increase the time period that the battery backup system can provide system power to the transmitter.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and form a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to accompanying descriptive matter, in which there are illustrated and described specific examples of an apparatus in accordance with the invention.